FALLUJAH, Iraq (CNN) -- Two Marines were killed and six others were wounded Friday in a suicide bombing near Fallujah, where U.S. Marines are preparing to reposition so Iraqi forces can take on a bigger role in fighting insurgents.

"There was a car bomb that was in the vicinity of Camp Fallujah, some distance away from the actual city of Fallujah," U.S. Army spokesman Brig. Gen. Mark Kimmitt said Friday.

Kimmitt said initial reports indicated the patrol was attacked by a suicide bomber driving a car with explosives inside, Kimmitt said.

Kimmitt said the Marines were repositioning their forces in Fallujah and that the move was not a retreat.

"There is a brigade [of Iraqis] being formed; we're working on forming the first battalion," Kimmitt said at a news conference. "We're certainly not withdrawing from Fallujah. Nothing could be further from the truth.

"Some areas are being turned over to this organization in a methodical matter. We understand a couple hundred of these prospective battalion members are going through a transfer of authority."

He said the first battalion of the Fallujah brigade will comprise former soldiers of the Iraqi army.

Such a move could help end a deadly siege in the city, military officials said.

Kimmitt said the goals in Fallujah remain the same: to collect all weapons and disarm insurgents.

There were no direct negotiations between the U.S. military and Iraqi insurgents, but military officials believe Iraqi forces may have better luck persuading the insurgents to lay down their arms.

The Iraqi generals said they would put together a force of 600 to 1,000 men, many of them from the Iraqi police forces or the former Iraqi army, the officials said. U.S. military officials said they were cautiously optimistic the generals could build the kind of force they described.

A statement from the Marines said the Iraqi brigade would be integrated with the U.S. forces.

"Until the battalion's units demonstrate a capability to man designated checkpoints and positions, Marines will continue to maintain a presence in and around Fallujah. Consistent with our duty to provide security, coalition forces will maintain their right of freedom of movement," the Marine statement said.

Families will be permitted back into the city as calm is restored, the statement said.

The number of families permitted back into Fallujah every day eventually will grow to 200.

Discussions have been going on in Fallujah between coalition and Iraqi authorities since mid-April.

Kimmitt said Marines would respond to an change in conditions as they saw fit.

Negotiations in Najaf

Meanwhile, the U.S. military is working to broker a deal with the radical Shiite cleric behind the standoff in Najaf.

Military officials are trying to bring together Najaf's leaders to agree to allow the Iraqi Civil Defense Corps (ICDC) to control the city, coalition military officials told CNN.

Militant Shiite cleric Muqtada al-Sadr has holed up at holy sites in Najaf with many of his supporters. Al-Sadr's militia has been attacking U.S. troops.

Some of the members of al-Sadr's militia, called the Mehdi Army, could be recruited to patrol Najaf as members of the ICDC if they agree to lay down their arms as insurgents, the sources said.

U.S. forces began new operations this week around the outskirts of Najaf, where Spanish troops were serving until their new prime minister pulled them out of the country.

In his weekly sermon, delivered in Najaf, al-Sadr kept up the hard-line rhetoric, calling the United States "the enemy of Islam."

"Some people have asked me to calm down my position and to avoid further escalation with the Americans and I reject all aspects of this occupation, and I will not give up defending the rights of the believers."

He also weighed in on the effort by the coalition to ease up on changes to the policy it calls "de-Baathification" -- the effort to lessen the influence of former loyalists to Saddam's Baath Party over the new Iraq.

The United States, though saying it is still committed to de-Baathification, said some people affiliated with the party, such as professionals and soldiers, were Baathist in name only. Officials have said that such people have skills that are needed in Iraq and should be hired. Such a move would keep the Sunnis from being alienated with the new government, officials said.

But al-Sadr said, "I will not accept the return of the former Baath Party members to play a role in Iraq, and if this happens so I will act against it."

Other developments

Arab television networks showed photographs Friday that were first broadcast by a U.S. television network that apparently show U.S. soldiers abusing detainees at the Abu Ghurayb prison outside Baghdad. The U.S. military says six U.S. soldiers have been charged with abusing inmates at the prison. (Full story)

A total of 738 U.S. troops have been killed in Iraq since the war began, 534 in combat and 204 in nonhostile incidents. Ten U.S. troops were killed Thursday in a series of attacks -- including eight who were killed in a car bomb attack in Mahmoudiya, south of Baghdad.

In a poll taken before the uptick in violence, 63 percent of Iraqis surveyed said they were convinced Iraq would be better off in five years. But a poll released Thursday found more than half of those Iraqis had an unfavorable view of both the United States and the situation in Iraq. (Full story)

Saturday marks the anniversary of President Bush's speech declaring the end of ''major combat operations" in Iraq.